Even with add ons the Bugeye wiring should be relatively simple.
Note the number of burned wires. Trace them out and identify what each one
Everything SHOULD be fused to prevent such occurrences of fire. On many
older cars, though, things like lights and ignition are not. Fuses should
be rated for the load they are supporting. A device that draws under 4
amps may have a 5 Amp fuse, for example. The blower motor will probably
have a 15 or 20 Amp fuse. 5 Amp fuses will usually pop before melting
wires. 15 or 20 will pass more current making melting and fire more
You are most likely going to find the wire for the blower motor shorted to
the chassis somewhere. When wires short they often times will melt
themselves and other wires if they are bundled together.
The horn in the Midget was grounded through the switch on the steering
wheel, IIRC. Your horn problem is possibly unrelated to the wiring
First thing to do is disconnect the battery. Pull the ground side so that
no further damage can occur. When you start poking around you may get a
flare up if you don't.
Next start tracing wires. I'd start at the blower motor and it's switch.
That is the first clue.
I would not order a new harness until after you ascertain the extent of the
damage. One 12 or 14 gauge wire can make a lot of smoke. If you're lucky
you'll find a short, some charred wire, and a simple repair. Look hard at
the fuse on that circuit, too. It should have blown long before you had
smoke and fire.